A6M8 Type 0 Model 64. Similar to the A6M6 but with the Sakae (now out of production) replaced by the Mitsubishi Kinsei 62 engine with 1,560 hp, 60% more powerful than the engine of the A6M2. This resulted in an extensively modified cowling and nose for the aircraft. Two prototypes were completed in April 1945 but the chaotic situation of Japanese industry and the end of the war obstructed the start of the ambitious program of production for 6,300 machines, none being completed.
Between March 1939 and August 1945, a grand total of 10,936 Zero fighters was produced in Japan, with 6,215 examples of the Mitsubishi design actually being produced under license by Nakajima. Description from warbirddepot.com. I searched for this on bing.com/images